1/*
2 * firmware_class.c - Multi purpose firmware loading support
3 *
4 * Copyright (c) 2003 Manuel Estrada Sainz
5 *
6 * Please see Documentation/firmware_class/ for more information.
7 *
8 */
9
10#include <linux/capability.h>
11#include <linux/device.h>
12#include <linux/module.h>
13#include <linux/init.h>
14#include <linux/timer.h>
15#include <linux/vmalloc.h>
16#include <linux/interrupt.h>
17#include <linux/bitops.h>
18#include <linux/mutex.h>
19#include <linux/workqueue.h>
20#include <linux/highmem.h>
21#include <linux/firmware.h>
22#include <linux/slab.h>
23#include <linux/sched.h>
24#include <linux/file.h>
25#include <linux/list.h>
26#include <linux/async.h>
27#include <linux/pm.h>
28#include <linux/suspend.h>
29#include <linux/syscore_ops.h>
30#include <linux/reboot.h>
31#include <linux/security.h>
32
33#include <generated/utsrelease.h>
34
35#include "base.h"
36
37MODULE_AUTHOR("Manuel Estrada Sainz");
38MODULE_DESCRIPTION("Multi purpose firmware loading support");
39MODULE_LICENSE("GPL");
40
41/* Builtin firmware support */
42
43#ifdef CONFIG_FW_LOADER
44
45extern struct builtin_fw __start_builtin_fw[];
46extern struct builtin_fw __end_builtin_fw[];
47
48static bool fw_get_builtin_firmware(struct firmware *fw, const char *name)
49{
50	struct builtin_fw *b_fw;
51
52	for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++) {
53		if (strcmp(name, b_fw->name) == 0) {
54			fw->size = b_fw->size;
55			fw->data = b_fw->data;
56			return true;
57		}
58	}
59
60	return false;
61}
62
63static bool fw_is_builtin_firmware(const struct firmware *fw)
64{
65	struct builtin_fw *b_fw;
66
67	for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++)
68		if (fw->data == b_fw->data)
69			return true;
70
71	return false;
72}
73
74#else /* Module case - no builtin firmware support */
75
76static inline bool fw_get_builtin_firmware(struct firmware *fw, const char *name)
77{
78	return false;
79}
80
81static inline bool fw_is_builtin_firmware(const struct firmware *fw)
82{
83	return false;
84}
85#endif
86
87enum {
88	FW_STATUS_LOADING,
89	FW_STATUS_DONE,
90	FW_STATUS_ABORT,
91};
92
93static int loading_timeout = 60;	/* In seconds */
94
95static inline long firmware_loading_timeout(void)
96{
97	return loading_timeout > 0 ? loading_timeout * HZ : MAX_JIFFY_OFFSET;
98}
99
100/* firmware behavior options */
101#define FW_OPT_UEVENT	(1U << 0)
102#define FW_OPT_NOWAIT	(1U << 1)
103#ifdef CONFIG_FW_LOADER_USER_HELPER
104#define FW_OPT_USERHELPER	(1U << 2)
105#else
106#define FW_OPT_USERHELPER	0
107#endif
108#ifdef CONFIG_FW_LOADER_USER_HELPER_FALLBACK
109#define FW_OPT_FALLBACK		FW_OPT_USERHELPER
110#else
111#define FW_OPT_FALLBACK		0
112#endif
113#define FW_OPT_NO_WARN	(1U << 3)
114
115struct firmware_cache {
116	/* firmware_buf instance will be added into the below list */
117	spinlock_t lock;
118	struct list_head head;
119	int state;
120
121#ifdef CONFIG_PM_SLEEP
122	/*
123	 * Names of firmware images which have been cached successfully
124	 * will be added into the below list so that device uncache
125	 * helper can trace which firmware images have been cached
126	 * before.
127	 */
128	spinlock_t name_lock;
129	struct list_head fw_names;
130
131	struct delayed_work work;
132
133	struct notifier_block   pm_notify;
134#endif
135};
136
137struct firmware_buf {
138	struct kref ref;
139	struct list_head list;
140	struct completion completion;
141	struct firmware_cache *fwc;
142	unsigned long status;
143	void *data;
144	size_t size;
145#ifdef CONFIG_FW_LOADER_USER_HELPER
146	bool is_paged_buf;
147	bool need_uevent;
148	struct page **pages;
149	int nr_pages;
150	int page_array_size;
151	struct list_head pending_list;
152#endif
153	const char *fw_id;
154};
155
156struct fw_cache_entry {
157	struct list_head list;
158	const char *name;
159};
160
161struct fw_name_devm {
162	unsigned long magic;
163	const char *name;
164};
165
166#define to_fwbuf(d) container_of(d, struct firmware_buf, ref)
167
168#define	FW_LOADER_NO_CACHE	0
169#define	FW_LOADER_START_CACHE	1
170
171static int fw_cache_piggyback_on_request(const char *name);
172
173/* fw_lock could be moved to 'struct firmware_priv' but since it is just
174 * guarding for corner cases a global lock should be OK */
175static DEFINE_MUTEX(fw_lock);
176
177static struct firmware_cache fw_cache;
178
179static struct firmware_buf *__allocate_fw_buf(const char *fw_name,
180					      struct firmware_cache *fwc)
181{
182	struct firmware_buf *buf;
183
184	buf = kzalloc(sizeof(*buf), GFP_ATOMIC);
185	if (!buf)
186		return NULL;
187
188	buf->fw_id = kstrdup_const(fw_name, GFP_ATOMIC);
189	if (!buf->fw_id) {
190		kfree(buf);
191		return NULL;
192	}
193
194	kref_init(&buf->ref);
195	buf->fwc = fwc;
196	init_completion(&buf->completion);
197#ifdef CONFIG_FW_LOADER_USER_HELPER
198	INIT_LIST_HEAD(&buf->pending_list);
199#endif
200
201	pr_debug("%s: fw-%s buf=%p\n", __func__, fw_name, buf);
202
203	return buf;
204}
205
206static struct firmware_buf *__fw_lookup_buf(const char *fw_name)
207{
208	struct firmware_buf *tmp;
209	struct firmware_cache *fwc = &fw_cache;
210
211	list_for_each_entry(tmp, &fwc->head, list)
212		if (!strcmp(tmp->fw_id, fw_name))
213			return tmp;
214	return NULL;
215}
216
217static int fw_lookup_and_allocate_buf(const char *fw_name,
218				      struct firmware_cache *fwc,
219				      struct firmware_buf **buf)
220{
221	struct firmware_buf *tmp;
222
223	spin_lock(&fwc->lock);
224	tmp = __fw_lookup_buf(fw_name);
225	if (tmp) {
226		kref_get(&tmp->ref);
227		spin_unlock(&fwc->lock);
228		*buf = tmp;
229		return 1;
230	}
231	tmp = __allocate_fw_buf(fw_name, fwc);
232	if (tmp)
233		list_add(&tmp->list, &fwc->head);
234	spin_unlock(&fwc->lock);
235
236	*buf = tmp;
237
238	return tmp ? 0 : -ENOMEM;
239}
240
241static void __fw_free_buf(struct kref *ref)
242	__releases(&fwc->lock)
243{
244	struct firmware_buf *buf = to_fwbuf(ref);
245	struct firmware_cache *fwc = buf->fwc;
246
247	pr_debug("%s: fw-%s buf=%p data=%p size=%u\n",
248		 __func__, buf->fw_id, buf, buf->data,
249		 (unsigned int)buf->size);
250
251	list_del(&buf->list);
252	spin_unlock(&fwc->lock);
253
254#ifdef CONFIG_FW_LOADER_USER_HELPER
255	if (buf->is_paged_buf) {
256		int i;
257		vunmap(buf->data);
258		for (i = 0; i < buf->nr_pages; i++)
259			__free_page(buf->pages[i]);
260		kfree(buf->pages);
261	} else
262#endif
263		vfree(buf->data);
264	kfree_const(buf->fw_id);
265	kfree(buf);
266}
267
268static void fw_free_buf(struct firmware_buf *buf)
269{
270	struct firmware_cache *fwc = buf->fwc;
271	spin_lock(&fwc->lock);
272	if (!kref_put(&buf->ref, __fw_free_buf))
273		spin_unlock(&fwc->lock);
274}
275
276/* direct firmware loading support */
277static char fw_path_para[256];
278static const char * const fw_path[] = {
279	fw_path_para,
280	"/lib/firmware/updates/" UTS_RELEASE,
281	"/lib/firmware/updates",
282	"/lib/firmware/" UTS_RELEASE,
283	"/lib/firmware"
284};
285
286/*
287 * Typical usage is that passing 'firmware_class.path=$CUSTOMIZED_PATH'
288 * from kernel command line because firmware_class is generally built in
289 * kernel instead of module.
290 */
291module_param_string(path, fw_path_para, sizeof(fw_path_para), 0644);
292MODULE_PARM_DESC(path, "customized firmware image search path with a higher priority than default path");
293
294static int fw_read_file_contents(struct file *file, struct firmware_buf *fw_buf)
295{
296	int size;
297	char *buf;
298	int rc;
299
300	if (!S_ISREG(file_inode(file)->i_mode))
301		return -EINVAL;
302	size = i_size_read(file_inode(file));
303	if (size <= 0)
304		return -EINVAL;
305	buf = vmalloc(size);
306	if (!buf)
307		return -ENOMEM;
308	rc = kernel_read(file, 0, buf, size);
309	if (rc != size) {
310		if (rc > 0)
311			rc = -EIO;
312		goto fail;
313	}
314	rc = security_kernel_fw_from_file(file, buf, size);
315	if (rc)
316		goto fail;
317	fw_buf->data = buf;
318	fw_buf->size = size;
319	return 0;
320fail:
321	vfree(buf);
322	return rc;
323}
324
325static int fw_get_filesystem_firmware(struct device *device,
326				       struct firmware_buf *buf)
327{
328	int i, len;
329	int rc = -ENOENT;
330	char *path;
331
332	path = __getname();
333	if (!path)
334		return -ENOMEM;
335
336	for (i = 0; i < ARRAY_SIZE(fw_path); i++) {
337		struct file *file;
338
339		/* skip the unset customized path */
340		if (!fw_path[i][0])
341			continue;
342
343		len = snprintf(path, PATH_MAX, "%s/%s",
344			       fw_path[i], buf->fw_id);
345		if (len >= PATH_MAX) {
346			rc = -ENAMETOOLONG;
347			break;
348		}
349
350		file = filp_open(path, O_RDONLY, 0);
351		if (IS_ERR(file))
352			continue;
353		rc = fw_read_file_contents(file, buf);
354		fput(file);
355		if (rc)
356			dev_warn(device, "firmware, attempted to load %s, but failed with error %d\n",
357				path, rc);
358		else
359			break;
360	}
361	__putname(path);
362
363	if (!rc) {
364		dev_dbg(device, "firmware: direct-loading firmware %s\n",
365			buf->fw_id);
366		mutex_lock(&fw_lock);
367		set_bit(FW_STATUS_DONE, &buf->status);
368		complete_all(&buf->completion);
369		mutex_unlock(&fw_lock);
370	}
371
372	return rc;
373}
374
375/* firmware holds the ownership of pages */
376static void firmware_free_data(const struct firmware *fw)
377{
378	/* Loaded directly? */
379	if (!fw->priv) {
380		vfree(fw->data);
381		return;
382	}
383	fw_free_buf(fw->priv);
384}
385
386/* store the pages buffer info firmware from buf */
387static void fw_set_page_data(struct firmware_buf *buf, struct firmware *fw)
388{
389	fw->priv = buf;
390#ifdef CONFIG_FW_LOADER_USER_HELPER
391	fw->pages = buf->pages;
392#endif
393	fw->size = buf->size;
394	fw->data = buf->data;
395
396	pr_debug("%s: fw-%s buf=%p data=%p size=%u\n",
397		 __func__, buf->fw_id, buf, buf->data,
398		 (unsigned int)buf->size);
399}
400
401#ifdef CONFIG_PM_SLEEP
402static void fw_name_devm_release(struct device *dev, void *res)
403{
404	struct fw_name_devm *fwn = res;
405
406	if (fwn->magic == (unsigned long)&fw_cache)
407		pr_debug("%s: fw_name-%s devm-%p released\n",
408				__func__, fwn->name, res);
409	kfree_const(fwn->name);
410}
411
412static int fw_devm_match(struct device *dev, void *res,
413		void *match_data)
414{
415	struct fw_name_devm *fwn = res;
416
417	return (fwn->magic == (unsigned long)&fw_cache) &&
418		!strcmp(fwn->name, match_data);
419}
420
421static struct fw_name_devm *fw_find_devm_name(struct device *dev,
422		const char *name)
423{
424	struct fw_name_devm *fwn;
425
426	fwn = devres_find(dev, fw_name_devm_release,
427			  fw_devm_match, (void *)name);
428	return fwn;
429}
430
431/* add firmware name into devres list */
432static int fw_add_devm_name(struct device *dev, const char *name)
433{
434	struct fw_name_devm *fwn;
435
436	fwn = fw_find_devm_name(dev, name);
437	if (fwn)
438		return 1;
439
440	fwn = devres_alloc(fw_name_devm_release, sizeof(struct fw_name_devm),
441			   GFP_KERNEL);
442	if (!fwn)
443		return -ENOMEM;
444	fwn->name = kstrdup_const(name, GFP_KERNEL);
445	if (!fwn->name) {
446		devres_free(fwn);
447		return -ENOMEM;
448	}
449
450	fwn->magic = (unsigned long)&fw_cache;
451	devres_add(dev, fwn);
452
453	return 0;
454}
455#else
456static int fw_add_devm_name(struct device *dev, const char *name)
457{
458	return 0;
459}
460#endif
461
462
463/*
464 * user-mode helper code
465 */
466#ifdef CONFIG_FW_LOADER_USER_HELPER
467struct firmware_priv {
468	bool nowait;
469	struct device dev;
470	struct firmware_buf *buf;
471	struct firmware *fw;
472};
473
474static struct firmware_priv *to_firmware_priv(struct device *dev)
475{
476	return container_of(dev, struct firmware_priv, dev);
477}
478
479static void __fw_load_abort(struct firmware_buf *buf)
480{
481	/*
482	 * There is a small window in which user can write to 'loading'
483	 * between loading done and disappearance of 'loading'
484	 */
485	if (test_bit(FW_STATUS_DONE, &buf->status))
486		return;
487
488	list_del_init(&buf->pending_list);
489	set_bit(FW_STATUS_ABORT, &buf->status);
490	complete_all(&buf->completion);
491}
492
493static void fw_load_abort(struct firmware_priv *fw_priv)
494{
495	struct firmware_buf *buf = fw_priv->buf;
496
497	__fw_load_abort(buf);
498
499	/* avoid user action after loading abort */
500	fw_priv->buf = NULL;
501}
502
503#define is_fw_load_aborted(buf)	\
504	test_bit(FW_STATUS_ABORT, &(buf)->status)
505
506static LIST_HEAD(pending_fw_head);
507
508/* reboot notifier for avoid deadlock with usermode_lock */
509static int fw_shutdown_notify(struct notifier_block *unused1,
510			      unsigned long unused2, void *unused3)
511{
512	mutex_lock(&fw_lock);
513	while (!list_empty(&pending_fw_head))
514		__fw_load_abort(list_first_entry(&pending_fw_head,
515					       struct firmware_buf,
516					       pending_list));
517	mutex_unlock(&fw_lock);
518	return NOTIFY_DONE;
519}
520
521static struct notifier_block fw_shutdown_nb = {
522	.notifier_call = fw_shutdown_notify,
523};
524
525static ssize_t timeout_show(struct class *class, struct class_attribute *attr,
526			    char *buf)
527{
528	return sprintf(buf, "%d\n", loading_timeout);
529}
530
531/**
532 * firmware_timeout_store - set number of seconds to wait for firmware
533 * @class: device class pointer
534 * @attr: device attribute pointer
535 * @buf: buffer to scan for timeout value
536 * @count: number of bytes in @buf
537 *
538 *	Sets the number of seconds to wait for the firmware.  Once
539 *	this expires an error will be returned to the driver and no
540 *	firmware will be provided.
541 *
542 *	Note: zero means 'wait forever'.
543 **/
544static ssize_t timeout_store(struct class *class, struct class_attribute *attr,
545			     const char *buf, size_t count)
546{
547	loading_timeout = simple_strtol(buf, NULL, 10);
548	if (loading_timeout < 0)
549		loading_timeout = 0;
550
551	return count;
552}
553
554static struct class_attribute firmware_class_attrs[] = {
555	__ATTR_RW(timeout),
556	__ATTR_NULL
557};
558
559static void fw_dev_release(struct device *dev)
560{
561	struct firmware_priv *fw_priv = to_firmware_priv(dev);
562
563	kfree(fw_priv);
564}
565
566static int do_firmware_uevent(struct firmware_priv *fw_priv, struct kobj_uevent_env *env)
567{
568	if (add_uevent_var(env, "FIRMWARE=%s", fw_priv->buf->fw_id))
569		return -ENOMEM;
570	if (add_uevent_var(env, "TIMEOUT=%i", loading_timeout))
571		return -ENOMEM;
572	if (add_uevent_var(env, "ASYNC=%d", fw_priv->nowait))
573		return -ENOMEM;
574
575	return 0;
576}
577
578static int firmware_uevent(struct device *dev, struct kobj_uevent_env *env)
579{
580	struct firmware_priv *fw_priv = to_firmware_priv(dev);
581	int err = 0;
582
583	mutex_lock(&fw_lock);
584	if (fw_priv->buf)
585		err = do_firmware_uevent(fw_priv, env);
586	mutex_unlock(&fw_lock);
587	return err;
588}
589
590static struct class firmware_class = {
591	.name		= "firmware",
592	.class_attrs	= firmware_class_attrs,
593	.dev_uevent	= firmware_uevent,
594	.dev_release	= fw_dev_release,
595};
596
597static ssize_t firmware_loading_show(struct device *dev,
598				     struct device_attribute *attr, char *buf)
599{
600	struct firmware_priv *fw_priv = to_firmware_priv(dev);
601	int loading = 0;
602
603	mutex_lock(&fw_lock);
604	if (fw_priv->buf)
605		loading = test_bit(FW_STATUS_LOADING, &fw_priv->buf->status);
606	mutex_unlock(&fw_lock);
607
608	return sprintf(buf, "%d\n", loading);
609}
610
611/* Some architectures don't have PAGE_KERNEL_RO */
612#ifndef PAGE_KERNEL_RO
613#define PAGE_KERNEL_RO PAGE_KERNEL
614#endif
615
616/* one pages buffer should be mapped/unmapped only once */
617static int fw_map_pages_buf(struct firmware_buf *buf)
618{
619	if (!buf->is_paged_buf)
620		return 0;
621
622	vunmap(buf->data);
623	buf->data = vmap(buf->pages, buf->nr_pages, 0, PAGE_KERNEL_RO);
624	if (!buf->data)
625		return -ENOMEM;
626	return 0;
627}
628
629/**
630 * firmware_loading_store - set value in the 'loading' control file
631 * @dev: device pointer
632 * @attr: device attribute pointer
633 * @buf: buffer to scan for loading control value
634 * @count: number of bytes in @buf
635 *
636 *	The relevant values are:
637 *
638 *	 1: Start a load, discarding any previous partial load.
639 *	 0: Conclude the load and hand the data to the driver code.
640 *	-1: Conclude the load with an error and discard any written data.
641 **/
642static ssize_t firmware_loading_store(struct device *dev,
643				      struct device_attribute *attr,
644				      const char *buf, size_t count)
645{
646	struct firmware_priv *fw_priv = to_firmware_priv(dev);
647	struct firmware_buf *fw_buf;
648	ssize_t written = count;
649	int loading = simple_strtol(buf, NULL, 10);
650	int i;
651
652	mutex_lock(&fw_lock);
653	fw_buf = fw_priv->buf;
654	if (!fw_buf)
655		goto out;
656
657	switch (loading) {
658	case 1:
659		/* discarding any previous partial load */
660		if (!test_bit(FW_STATUS_DONE, &fw_buf->status)) {
661			for (i = 0; i < fw_buf->nr_pages; i++)
662				__free_page(fw_buf->pages[i]);
663			kfree(fw_buf->pages);
664			fw_buf->pages = NULL;
665			fw_buf->page_array_size = 0;
666			fw_buf->nr_pages = 0;
667			set_bit(FW_STATUS_LOADING, &fw_buf->status);
668		}
669		break;
670	case 0:
671		if (test_bit(FW_STATUS_LOADING, &fw_buf->status)) {
672			int rc;
673
674			set_bit(FW_STATUS_DONE, &fw_buf->status);
675			clear_bit(FW_STATUS_LOADING, &fw_buf->status);
676
677			/*
678			 * Several loading requests may be pending on
679			 * one same firmware buf, so let all requests
680			 * see the mapped 'buf->data' once the loading
681			 * is completed.
682			 * */
683			rc = fw_map_pages_buf(fw_buf);
684			if (rc)
685				dev_err(dev, "%s: map pages failed\n",
686					__func__);
687			else
688				rc = security_kernel_fw_from_file(NULL,
689						fw_buf->data, fw_buf->size);
690
691			/*
692			 * Same logic as fw_load_abort, only the DONE bit
693			 * is ignored and we set ABORT only on failure.
694			 */
695			list_del_init(&fw_buf->pending_list);
696			if (rc) {
697				set_bit(FW_STATUS_ABORT, &fw_buf->status);
698				written = rc;
699			}
700			complete_all(&fw_buf->completion);
701			break;
702		}
703		/* fallthrough */
704	default:
705		dev_err(dev, "%s: unexpected value (%d)\n", __func__, loading);
706		/* fallthrough */
707	case -1:
708		fw_load_abort(fw_priv);
709		break;
710	}
711out:
712	mutex_unlock(&fw_lock);
713	return written;
714}
715
716static DEVICE_ATTR(loading, 0644, firmware_loading_show, firmware_loading_store);
717
718static ssize_t firmware_data_read(struct file *filp, struct kobject *kobj,
719				  struct bin_attribute *bin_attr,
720				  char *buffer, loff_t offset, size_t count)
721{
722	struct device *dev = kobj_to_dev(kobj);
723	struct firmware_priv *fw_priv = to_firmware_priv(dev);
724	struct firmware_buf *buf;
725	ssize_t ret_count;
726
727	mutex_lock(&fw_lock);
728	buf = fw_priv->buf;
729	if (!buf || test_bit(FW_STATUS_DONE, &buf->status)) {
730		ret_count = -ENODEV;
731		goto out;
732	}
733	if (offset > buf->size) {
734		ret_count = 0;
735		goto out;
736	}
737	if (count > buf->size - offset)
738		count = buf->size - offset;
739
740	ret_count = count;
741
742	while (count) {
743		void *page_data;
744		int page_nr = offset >> PAGE_SHIFT;
745		int page_ofs = offset & (PAGE_SIZE-1);
746		int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);
747
748		page_data = kmap(buf->pages[page_nr]);
749
750		memcpy(buffer, page_data + page_ofs, page_cnt);
751
752		kunmap(buf->pages[page_nr]);
753		buffer += page_cnt;
754		offset += page_cnt;
755		count -= page_cnt;
756	}
757out:
758	mutex_unlock(&fw_lock);
759	return ret_count;
760}
761
762static int fw_realloc_buffer(struct firmware_priv *fw_priv, int min_size)
763{
764	struct firmware_buf *buf = fw_priv->buf;
765	int pages_needed = PAGE_ALIGN(min_size) >> PAGE_SHIFT;
766
767	/* If the array of pages is too small, grow it... */
768	if (buf->page_array_size < pages_needed) {
769		int new_array_size = max(pages_needed,
770					 buf->page_array_size * 2);
771		struct page **new_pages;
772
773		new_pages = kmalloc(new_array_size * sizeof(void *),
774				    GFP_KERNEL);
775		if (!new_pages) {
776			fw_load_abort(fw_priv);
777			return -ENOMEM;
778		}
779		memcpy(new_pages, buf->pages,
780		       buf->page_array_size * sizeof(void *));
781		memset(&new_pages[buf->page_array_size], 0, sizeof(void *) *
782		       (new_array_size - buf->page_array_size));
783		kfree(buf->pages);
784		buf->pages = new_pages;
785		buf->page_array_size = new_array_size;
786	}
787
788	while (buf->nr_pages < pages_needed) {
789		buf->pages[buf->nr_pages] =
790			alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
791
792		if (!buf->pages[buf->nr_pages]) {
793			fw_load_abort(fw_priv);
794			return -ENOMEM;
795		}
796		buf->nr_pages++;
797	}
798	return 0;
799}
800
801/**
802 * firmware_data_write - write method for firmware
803 * @filp: open sysfs file
804 * @kobj: kobject for the device
805 * @bin_attr: bin_attr structure
806 * @buffer: buffer being written
807 * @offset: buffer offset for write in total data store area
808 * @count: buffer size
809 *
810 *	Data written to the 'data' attribute will be later handed to
811 *	the driver as a firmware image.
812 **/
813static ssize_t firmware_data_write(struct file *filp, struct kobject *kobj,
814				   struct bin_attribute *bin_attr,
815				   char *buffer, loff_t offset, size_t count)
816{
817	struct device *dev = kobj_to_dev(kobj);
818	struct firmware_priv *fw_priv = to_firmware_priv(dev);
819	struct firmware_buf *buf;
820	ssize_t retval;
821
822	if (!capable(CAP_SYS_RAWIO))
823		return -EPERM;
824
825	mutex_lock(&fw_lock);
826	buf = fw_priv->buf;
827	if (!buf || test_bit(FW_STATUS_DONE, &buf->status)) {
828		retval = -ENODEV;
829		goto out;
830	}
831
832	retval = fw_realloc_buffer(fw_priv, offset + count);
833	if (retval)
834		goto out;
835
836	retval = count;
837
838	while (count) {
839		void *page_data;
840		int page_nr = offset >> PAGE_SHIFT;
841		int page_ofs = offset & (PAGE_SIZE - 1);
842		int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);
843
844		page_data = kmap(buf->pages[page_nr]);
845
846		memcpy(page_data + page_ofs, buffer, page_cnt);
847
848		kunmap(buf->pages[page_nr]);
849		buffer += page_cnt;
850		offset += page_cnt;
851		count -= page_cnt;
852	}
853
854	buf->size = max_t(size_t, offset, buf->size);
855out:
856	mutex_unlock(&fw_lock);
857	return retval;
858}
859
860static struct bin_attribute firmware_attr_data = {
861	.attr = { .name = "data", .mode = 0644 },
862	.size = 0,
863	.read = firmware_data_read,
864	.write = firmware_data_write,
865};
866
867static struct attribute *fw_dev_attrs[] = {
868	&dev_attr_loading.attr,
869	NULL
870};
871
872static struct bin_attribute *fw_dev_bin_attrs[] = {
873	&firmware_attr_data,
874	NULL
875};
876
877static const struct attribute_group fw_dev_attr_group = {
878	.attrs = fw_dev_attrs,
879	.bin_attrs = fw_dev_bin_attrs,
880};
881
882static const struct attribute_group *fw_dev_attr_groups[] = {
883	&fw_dev_attr_group,
884	NULL
885};
886
887static struct firmware_priv *
888fw_create_instance(struct firmware *firmware, const char *fw_name,
889		   struct device *device, unsigned int opt_flags)
890{
891	struct firmware_priv *fw_priv;
892	struct device *f_dev;
893
894	fw_priv = kzalloc(sizeof(*fw_priv), GFP_KERNEL);
895	if (!fw_priv) {
896		fw_priv = ERR_PTR(-ENOMEM);
897		goto exit;
898	}
899
900	fw_priv->nowait = !!(opt_flags & FW_OPT_NOWAIT);
901	fw_priv->fw = firmware;
902	f_dev = &fw_priv->dev;
903
904	device_initialize(f_dev);
905	dev_set_name(f_dev, "%s", fw_name);
906	f_dev->parent = device;
907	f_dev->class = &firmware_class;
908	f_dev->groups = fw_dev_attr_groups;
909exit:
910	return fw_priv;
911}
912
913/* load a firmware via user helper */
914static int _request_firmware_load(struct firmware_priv *fw_priv,
915				  unsigned int opt_flags, long timeout)
916{
917	int retval = 0;
918	struct device *f_dev = &fw_priv->dev;
919	struct firmware_buf *buf = fw_priv->buf;
920
921	/* fall back on userspace loading */
922	buf->is_paged_buf = true;
923
924	dev_set_uevent_suppress(f_dev, true);
925
926	retval = device_add(f_dev);
927	if (retval) {
928		dev_err(f_dev, "%s: device_register failed\n", __func__);
929		goto err_put_dev;
930	}
931
932	mutex_lock(&fw_lock);
933	list_add(&buf->pending_list, &pending_fw_head);
934	mutex_unlock(&fw_lock);
935
936	if (opt_flags & FW_OPT_UEVENT) {
937		buf->need_uevent = true;
938		dev_set_uevent_suppress(f_dev, false);
939		dev_dbg(f_dev, "firmware: requesting %s\n", buf->fw_id);
940		kobject_uevent(&fw_priv->dev.kobj, KOBJ_ADD);
941	} else {
942		timeout = MAX_JIFFY_OFFSET;
943	}
944
945	retval = wait_for_completion_interruptible_timeout(&buf->completion,
946			timeout);
947	if (retval == -ERESTARTSYS || !retval) {
948		mutex_lock(&fw_lock);
949		fw_load_abort(fw_priv);
950		mutex_unlock(&fw_lock);
951	} else if (retval > 0) {
952		retval = 0;
953	}
954
955	if (is_fw_load_aborted(buf))
956		retval = -EAGAIN;
957	else if (!buf->data)
958		retval = -ENOMEM;
959
960	device_del(f_dev);
961err_put_dev:
962	put_device(f_dev);
963	return retval;
964}
965
966static int fw_load_from_user_helper(struct firmware *firmware,
967				    const char *name, struct device *device,
968				    unsigned int opt_flags, long timeout)
969{
970	struct firmware_priv *fw_priv;
971
972	fw_priv = fw_create_instance(firmware, name, device, opt_flags);
973	if (IS_ERR(fw_priv))
974		return PTR_ERR(fw_priv);
975
976	fw_priv->buf = firmware->priv;
977	return _request_firmware_load(fw_priv, opt_flags, timeout);
978}
979
980#ifdef CONFIG_PM_SLEEP
981/* kill pending requests without uevent to avoid blocking suspend */
982static void kill_requests_without_uevent(void)
983{
984	struct firmware_buf *buf;
985	struct firmware_buf *next;
986
987	mutex_lock(&fw_lock);
988	list_for_each_entry_safe(buf, next, &pending_fw_head, pending_list) {
989		if (!buf->need_uevent)
990			 __fw_load_abort(buf);
991	}
992	mutex_unlock(&fw_lock);
993}
994#endif
995
996#else /* CONFIG_FW_LOADER_USER_HELPER */
997static inline int
998fw_load_from_user_helper(struct firmware *firmware, const char *name,
999			 struct device *device, unsigned int opt_flags,
1000			 long timeout)
1001{
1002	return -ENOENT;
1003}
1004
1005/* No abort during direct loading */
1006#define is_fw_load_aborted(buf) false
1007
1008#ifdef CONFIG_PM_SLEEP
1009static inline void kill_requests_without_uevent(void) { }
1010#endif
1011
1012#endif /* CONFIG_FW_LOADER_USER_HELPER */
1013
1014
1015/* wait until the shared firmware_buf becomes ready (or error) */
1016static int sync_cached_firmware_buf(struct firmware_buf *buf)
1017{
1018	int ret = 0;
1019
1020	mutex_lock(&fw_lock);
1021	while (!test_bit(FW_STATUS_DONE, &buf->status)) {
1022		if (is_fw_load_aborted(buf)) {
1023			ret = -ENOENT;
1024			break;
1025		}
1026		mutex_unlock(&fw_lock);
1027		ret = wait_for_completion_interruptible(&buf->completion);
1028		mutex_lock(&fw_lock);
1029	}
1030	mutex_unlock(&fw_lock);
1031	return ret;
1032}
1033
1034/* prepare firmware and firmware_buf structs;
1035 * return 0 if a firmware is already assigned, 1 if need to load one,
1036 * or a negative error code
1037 */
1038static int
1039_request_firmware_prepare(struct firmware **firmware_p, const char *name,
1040			  struct device *device)
1041{
1042	struct firmware *firmware;
1043	struct firmware_buf *buf;
1044	int ret;
1045
1046	*firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_KERNEL);
1047	if (!firmware) {
1048		dev_err(device, "%s: kmalloc(struct firmware) failed\n",
1049			__func__);
1050		return -ENOMEM;
1051	}
1052
1053	if (fw_get_builtin_firmware(firmware, name)) {
1054		dev_dbg(device, "firmware: using built-in firmware %s\n", name);
1055		return 0; /* assigned */
1056	}
1057
1058	ret = fw_lookup_and_allocate_buf(name, &fw_cache, &buf);
1059
1060	/*
1061	 * bind with 'buf' now to avoid warning in failure path
1062	 * of requesting firmware.
1063	 */
1064	firmware->priv = buf;
1065
1066	if (ret > 0) {
1067		ret = sync_cached_firmware_buf(buf);
1068		if (!ret) {
1069			fw_set_page_data(buf, firmware);
1070			return 0; /* assigned */
1071		}
1072	}
1073
1074	if (ret < 0)
1075		return ret;
1076	return 1; /* need to load */
1077}
1078
1079static int assign_firmware_buf(struct firmware *fw, struct device *device,
1080			       unsigned int opt_flags)
1081{
1082	struct firmware_buf *buf = fw->priv;
1083
1084	mutex_lock(&fw_lock);
1085	if (!buf->size || is_fw_load_aborted(buf)) {
1086		mutex_unlock(&fw_lock);
1087		return -ENOENT;
1088	}
1089
1090	/*
1091	 * add firmware name into devres list so that we can auto cache
1092	 * and uncache firmware for device.
1093	 *
1094	 * device may has been deleted already, but the problem
1095	 * should be fixed in devres or driver core.
1096	 */
1097	/* don't cache firmware handled without uevent */
1098	if (device && (opt_flags & FW_OPT_UEVENT))
1099		fw_add_devm_name(device, buf->fw_id);
1100
1101	/*
1102	 * After caching firmware image is started, let it piggyback
1103	 * on request firmware.
1104	 */
1105	if (buf->fwc->state == FW_LOADER_START_CACHE) {
1106		if (fw_cache_piggyback_on_request(buf->fw_id))
1107			kref_get(&buf->ref);
1108	}
1109
1110	/* pass the pages buffer to driver at the last minute */
1111	fw_set_page_data(buf, fw);
1112	mutex_unlock(&fw_lock);
1113	return 0;
1114}
1115
1116/* called from request_firmware() and request_firmware_work_func() */
1117static int
1118_request_firmware(const struct firmware **firmware_p, const char *name,
1119		  struct device *device, unsigned int opt_flags)
1120{
1121	struct firmware *fw;
1122	long timeout;
1123	int ret;
1124
1125	if (!firmware_p)
1126		return -EINVAL;
1127
1128	if (!name || name[0] == '\0')
1129		return -EINVAL;
1130
1131	ret = _request_firmware_prepare(&fw, name, device);
1132	if (ret <= 0) /* error or already assigned */
1133		goto out;
1134
1135	ret = 0;
1136	timeout = firmware_loading_timeout();
1137	if (opt_flags & FW_OPT_NOWAIT) {
1138		timeout = usermodehelper_read_lock_wait(timeout);
1139		if (!timeout) {
1140			dev_dbg(device, "firmware: %s loading timed out\n",
1141				name);
1142			ret = -EBUSY;
1143			goto out;
1144		}
1145	} else {
1146		ret = usermodehelper_read_trylock();
1147		if (WARN_ON(ret)) {
1148			dev_err(device, "firmware: %s will not be loaded\n",
1149				name);
1150			goto out;
1151		}
1152	}
1153
1154	ret = fw_get_filesystem_firmware(device, fw->priv);
1155	if (ret) {
1156		if (!(opt_flags & FW_OPT_NO_WARN))
1157			dev_warn(device,
1158				 "Direct firmware load for %s failed with error %d\n",
1159				 name, ret);
1160		if (opt_flags & FW_OPT_USERHELPER) {
1161			dev_warn(device, "Falling back to user helper\n");
1162			ret = fw_load_from_user_helper(fw, name, device,
1163						       opt_flags, timeout);
1164		}
1165	}
1166
1167	if (!ret)
1168		ret = assign_firmware_buf(fw, device, opt_flags);
1169
1170	usermodehelper_read_unlock();
1171
1172 out:
1173	if (ret < 0) {
1174		release_firmware(fw);
1175		fw = NULL;
1176	}
1177
1178	*firmware_p = fw;
1179	return ret;
1180}
1181
1182/**
1183 * request_firmware: - send firmware request and wait for it
1184 * @firmware_p: pointer to firmware image
1185 * @name: name of firmware file
1186 * @device: device for which firmware is being loaded
1187 *
1188 *      @firmware_p will be used to return a firmware image by the name
1189 *      of @name for device @device.
1190 *
1191 *      Should be called from user context where sleeping is allowed.
1192 *
1193 *      @name will be used as $FIRMWARE in the uevent environment and
1194 *      should be distinctive enough not to be confused with any other
1195 *      firmware image for this or any other device.
1196 *
1197 *	Caller must hold the reference count of @device.
1198 *
1199 *	The function can be called safely inside device's suspend and
1200 *	resume callback.
1201 **/
1202int
1203request_firmware(const struct firmware **firmware_p, const char *name,
1204		 struct device *device)
1205{
1206	int ret;
1207
1208	/* Need to pin this module until return */
1209	__module_get(THIS_MODULE);
1210	ret = _request_firmware(firmware_p, name, device,
1211				FW_OPT_UEVENT | FW_OPT_FALLBACK);
1212	module_put(THIS_MODULE);
1213	return ret;
1214}
1215EXPORT_SYMBOL(request_firmware);
1216
1217/**
1218 * request_firmware_direct: - load firmware directly without usermode helper
1219 * @firmware_p: pointer to firmware image
1220 * @name: name of firmware file
1221 * @device: device for which firmware is being loaded
1222 *
1223 * This function works pretty much like request_firmware(), but this doesn't
1224 * fall back to usermode helper even if the firmware couldn't be loaded
1225 * directly from fs.  Hence it's useful for loading optional firmwares, which
1226 * aren't always present, without extra long timeouts of udev.
1227 **/
1228int request_firmware_direct(const struct firmware **firmware_p,
1229			    const char *name, struct device *device)
1230{
1231	int ret;
1232
1233	__module_get(THIS_MODULE);
1234	ret = _request_firmware(firmware_p, name, device,
1235				FW_OPT_UEVENT | FW_OPT_NO_WARN);
1236	module_put(THIS_MODULE);
1237	return ret;
1238}
1239EXPORT_SYMBOL_GPL(request_firmware_direct);
1240
1241/**
1242 * release_firmware: - release the resource associated with a firmware image
1243 * @fw: firmware resource to release
1244 **/
1245void release_firmware(const struct firmware *fw)
1246{
1247	if (fw) {
1248		if (!fw_is_builtin_firmware(fw))
1249			firmware_free_data(fw);
1250		kfree(fw);
1251	}
1252}
1253EXPORT_SYMBOL(release_firmware);
1254
1255/* Async support */
1256struct firmware_work {
1257	struct work_struct work;
1258	struct module *module;
1259	const char *name;
1260	struct device *device;
1261	void *context;
1262	void (*cont)(const struct firmware *fw, void *context);
1263	unsigned int opt_flags;
1264};
1265
1266static void request_firmware_work_func(struct work_struct *work)
1267{
1268	struct firmware_work *fw_work;
1269	const struct firmware *fw;
1270
1271	fw_work = container_of(work, struct firmware_work, work);
1272
1273	_request_firmware(&fw, fw_work->name, fw_work->device,
1274			  fw_work->opt_flags);
1275	fw_work->cont(fw, fw_work->context);
1276	put_device(fw_work->device); /* taken in request_firmware_nowait() */
1277
1278	module_put(fw_work->module);
1279	kfree_const(fw_work->name);
1280	kfree(fw_work);
1281}
1282
1283/**
1284 * request_firmware_nowait - asynchronous version of request_firmware
1285 * @module: module requesting the firmware
1286 * @uevent: sends uevent to copy the firmware image if this flag
1287 *	is non-zero else the firmware copy must be done manually.
1288 * @name: name of firmware file
1289 * @device: device for which firmware is being loaded
1290 * @gfp: allocation flags
1291 * @context: will be passed over to @cont, and
1292 *	@fw may be %NULL if firmware request fails.
1293 * @cont: function will be called asynchronously when the firmware
1294 *	request is over.
1295 *
1296 *	Caller must hold the reference count of @device.
1297 *
1298 *	Asynchronous variant of request_firmware() for user contexts:
1299 *		- sleep for as small periods as possible since it may
1300 *		increase kernel boot time of built-in device drivers
1301 *		requesting firmware in their ->probe() methods, if
1302 *		@gfp is GFP_KERNEL.
1303 *
1304 *		- can't sleep at all if @gfp is GFP_ATOMIC.
1305 **/
1306int
1307request_firmware_nowait(
1308	struct module *module, bool uevent,
1309	const char *name, struct device *device, gfp_t gfp, void *context,
1310	void (*cont)(const struct firmware *fw, void *context))
1311{
1312	struct firmware_work *fw_work;
1313
1314	fw_work = kzalloc(sizeof(struct firmware_work), gfp);
1315	if (!fw_work)
1316		return -ENOMEM;
1317
1318	fw_work->module = module;
1319	fw_work->name = kstrdup_const(name, gfp);
1320	if (!fw_work->name) {
1321		kfree(fw_work);
1322		return -ENOMEM;
1323	}
1324	fw_work->device = device;
1325	fw_work->context = context;
1326	fw_work->cont = cont;
1327	fw_work->opt_flags = FW_OPT_NOWAIT | FW_OPT_FALLBACK |
1328		(uevent ? FW_OPT_UEVENT : FW_OPT_USERHELPER);
1329
1330	if (!try_module_get(module)) {
1331		kfree_const(fw_work->name);
1332		kfree(fw_work);
1333		return -EFAULT;
1334	}
1335
1336	get_device(fw_work->device);
1337	INIT_WORK(&fw_work->work, request_firmware_work_func);
1338	schedule_work(&fw_work->work);
1339	return 0;
1340}
1341EXPORT_SYMBOL(request_firmware_nowait);
1342
1343#ifdef CONFIG_PM_SLEEP
1344static ASYNC_DOMAIN_EXCLUSIVE(fw_cache_domain);
1345
1346/**
1347 * cache_firmware - cache one firmware image in kernel memory space
1348 * @fw_name: the firmware image name
1349 *
1350 * Cache firmware in kernel memory so that drivers can use it when
1351 * system isn't ready for them to request firmware image from userspace.
1352 * Once it returns successfully, driver can use request_firmware or its
1353 * nowait version to get the cached firmware without any interacting
1354 * with userspace
1355 *
1356 * Return 0 if the firmware image has been cached successfully
1357 * Return !0 otherwise
1358 *
1359 */
1360static int cache_firmware(const char *fw_name)
1361{
1362	int ret;
1363	const struct firmware *fw;
1364
1365	pr_debug("%s: %s\n", __func__, fw_name);
1366
1367	ret = request_firmware(&fw, fw_name, NULL);
1368	if (!ret)
1369		kfree(fw);
1370
1371	pr_debug("%s: %s ret=%d\n", __func__, fw_name, ret);
1372
1373	return ret;
1374}
1375
1376static struct firmware_buf *fw_lookup_buf(const char *fw_name)
1377{
1378	struct firmware_buf *tmp;
1379	struct firmware_cache *fwc = &fw_cache;
1380
1381	spin_lock(&fwc->lock);
1382	tmp = __fw_lookup_buf(fw_name);
1383	spin_unlock(&fwc->lock);
1384
1385	return tmp;
1386}
1387
1388/**
1389 * uncache_firmware - remove one cached firmware image
1390 * @fw_name: the firmware image name
1391 *
1392 * Uncache one firmware image which has been cached successfully
1393 * before.
1394 *
1395 * Return 0 if the firmware cache has been removed successfully
1396 * Return !0 otherwise
1397 *
1398 */
1399static int uncache_firmware(const char *fw_name)
1400{
1401	struct firmware_buf *buf;
1402	struct firmware fw;
1403
1404	pr_debug("%s: %s\n", __func__, fw_name);
1405
1406	if (fw_get_builtin_firmware(&fw, fw_name))
1407		return 0;
1408
1409	buf = fw_lookup_buf(fw_name);
1410	if (buf) {
1411		fw_free_buf(buf);
1412		return 0;
1413	}
1414
1415	return -EINVAL;
1416}
1417
1418static struct fw_cache_entry *alloc_fw_cache_entry(const char *name)
1419{
1420	struct fw_cache_entry *fce;
1421
1422	fce = kzalloc(sizeof(*fce), GFP_ATOMIC);
1423	if (!fce)
1424		goto exit;
1425
1426	fce->name = kstrdup_const(name, GFP_ATOMIC);
1427	if (!fce->name) {
1428		kfree(fce);
1429		fce = NULL;
1430		goto exit;
1431	}
1432exit:
1433	return fce;
1434}
1435
1436static int __fw_entry_found(const char *name)
1437{
1438	struct firmware_cache *fwc = &fw_cache;
1439	struct fw_cache_entry *fce;
1440
1441	list_for_each_entry(fce, &fwc->fw_names, list) {
1442		if (!strcmp(fce->name, name))
1443			return 1;
1444	}
1445	return 0;
1446}
1447
1448static int fw_cache_piggyback_on_request(const char *name)
1449{
1450	struct firmware_cache *fwc = &fw_cache;
1451	struct fw_cache_entry *fce;
1452	int ret = 0;
1453
1454	spin_lock(&fwc->name_lock);
1455	if (__fw_entry_found(name))
1456		goto found;
1457
1458	fce = alloc_fw_cache_entry(name);
1459	if (fce) {
1460		ret = 1;
1461		list_add(&fce->list, &fwc->fw_names);
1462		pr_debug("%s: fw: %s\n", __func__, name);
1463	}
1464found:
1465	spin_unlock(&fwc->name_lock);
1466	return ret;
1467}
1468
1469static void free_fw_cache_entry(struct fw_cache_entry *fce)
1470{
1471	kfree_const(fce->name);
1472	kfree(fce);
1473}
1474
1475static void __async_dev_cache_fw_image(void *fw_entry,
1476				       async_cookie_t cookie)
1477{
1478	struct fw_cache_entry *fce = fw_entry;
1479	struct firmware_cache *fwc = &fw_cache;
1480	int ret;
1481
1482	ret = cache_firmware(fce->name);
1483	if (ret) {
1484		spin_lock(&fwc->name_lock);
1485		list_del(&fce->list);
1486		spin_unlock(&fwc->name_lock);
1487
1488		free_fw_cache_entry(fce);
1489	}
1490}
1491
1492/* called with dev->devres_lock held */
1493static void dev_create_fw_entry(struct device *dev, void *res,
1494				void *data)
1495{
1496	struct fw_name_devm *fwn = res;
1497	const char *fw_name = fwn->name;
1498	struct list_head *head = data;
1499	struct fw_cache_entry *fce;
1500
1501	fce = alloc_fw_cache_entry(fw_name);
1502	if (fce)
1503		list_add(&fce->list, head);
1504}
1505
1506static int devm_name_match(struct device *dev, void *res,
1507			   void *match_data)
1508{
1509	struct fw_name_devm *fwn = res;
1510	return (fwn->magic == (unsigned long)match_data);
1511}
1512
1513static void dev_cache_fw_image(struct device *dev, void *data)
1514{
1515	LIST_HEAD(todo);
1516	struct fw_cache_entry *fce;
1517	struct fw_cache_entry *fce_next;
1518	struct firmware_cache *fwc = &fw_cache;
1519
1520	devres_for_each_res(dev, fw_name_devm_release,
1521			    devm_name_match, &fw_cache,
1522			    dev_create_fw_entry, &todo);
1523
1524	list_for_each_entry_safe(fce, fce_next, &todo, list) {
1525		list_del(&fce->list);
1526
1527		spin_lock(&fwc->name_lock);
1528		/* only one cache entry for one firmware */
1529		if (!__fw_entry_found(fce->name)) {
1530			list_add(&fce->list, &fwc->fw_names);
1531		} else {
1532			free_fw_cache_entry(fce);
1533			fce = NULL;
1534		}
1535		spin_unlock(&fwc->name_lock);
1536
1537		if (fce)
1538			async_schedule_domain(__async_dev_cache_fw_image,
1539					      (void *)fce,
1540					      &fw_cache_domain);
1541	}
1542}
1543
1544static void __device_uncache_fw_images(void)
1545{
1546	struct firmware_cache *fwc = &fw_cache;
1547	struct fw_cache_entry *fce;
1548
1549	spin_lock(&fwc->name_lock);
1550	while (!list_empty(&fwc->fw_names)) {
1551		fce = list_entry(fwc->fw_names.next,
1552				struct fw_cache_entry, list);
1553		list_del(&fce->list);
1554		spin_unlock(&fwc->name_lock);
1555
1556		uncache_firmware(fce->name);
1557		free_fw_cache_entry(fce);
1558
1559		spin_lock(&fwc->name_lock);
1560	}
1561	spin_unlock(&fwc->name_lock);
1562}
1563
1564/**
1565 * device_cache_fw_images - cache devices' firmware
1566 *
1567 * If one device called request_firmware or its nowait version
1568 * successfully before, the firmware names are recored into the
1569 * device's devres link list, so device_cache_fw_images can call
1570 * cache_firmware() to cache these firmwares for the device,
1571 * then the device driver can load its firmwares easily at
1572 * time when system is not ready to complete loading firmware.
1573 */
1574static void device_cache_fw_images(void)
1575{
1576	struct firmware_cache *fwc = &fw_cache;
1577	int old_timeout;
1578	DEFINE_WAIT(wait);
1579
1580	pr_debug("%s\n", __func__);
1581
1582	/* cancel uncache work */
1583	cancel_delayed_work_sync(&fwc->work);
1584
1585	/*
1586	 * use small loading timeout for caching devices' firmware
1587	 * because all these firmware images have been loaded
1588	 * successfully at lease once, also system is ready for
1589	 * completing firmware loading now. The maximum size of
1590	 * firmware in current distributions is about 2M bytes,
1591	 * so 10 secs should be enough.
1592	 */
1593	old_timeout = loading_timeout;
1594	loading_timeout = 10;
1595
1596	mutex_lock(&fw_lock);
1597	fwc->state = FW_LOADER_START_CACHE;
1598	dpm_for_each_dev(NULL, dev_cache_fw_image);
1599	mutex_unlock(&fw_lock);
1600
1601	/* wait for completion of caching firmware for all devices */
1602	async_synchronize_full_domain(&fw_cache_domain);
1603
1604	loading_timeout = old_timeout;
1605}
1606
1607/**
1608 * device_uncache_fw_images - uncache devices' firmware
1609 *
1610 * uncache all firmwares which have been cached successfully
1611 * by device_uncache_fw_images earlier
1612 */
1613static void device_uncache_fw_images(void)
1614{
1615	pr_debug("%s\n", __func__);
1616	__device_uncache_fw_images();
1617}
1618
1619static void device_uncache_fw_images_work(struct work_struct *work)
1620{
1621	device_uncache_fw_images();
1622}
1623
1624/**
1625 * device_uncache_fw_images_delay - uncache devices firmwares
1626 * @delay: number of milliseconds to delay uncache device firmwares
1627 *
1628 * uncache all devices's firmwares which has been cached successfully
1629 * by device_cache_fw_images after @delay milliseconds.
1630 */
1631static void device_uncache_fw_images_delay(unsigned long delay)
1632{
1633	queue_delayed_work(system_power_efficient_wq, &fw_cache.work,
1634			   msecs_to_jiffies(delay));
1635}
1636
1637static int fw_pm_notify(struct notifier_block *notify_block,
1638			unsigned long mode, void *unused)
1639{
1640	switch (mode) {
1641	case PM_HIBERNATION_PREPARE:
1642	case PM_SUSPEND_PREPARE:
1643	case PM_RESTORE_PREPARE:
1644		kill_requests_without_uevent();
1645		device_cache_fw_images();
1646		break;
1647
1648	case PM_POST_SUSPEND:
1649	case PM_POST_HIBERNATION:
1650	case PM_POST_RESTORE:
1651		/*
1652		 * In case that system sleep failed and syscore_suspend is
1653		 * not called.
1654		 */
1655		mutex_lock(&fw_lock);
1656		fw_cache.state = FW_LOADER_NO_CACHE;
1657		mutex_unlock(&fw_lock);
1658
1659		device_uncache_fw_images_delay(10 * MSEC_PER_SEC);
1660		break;
1661	}
1662
1663	return 0;
1664}
1665
1666/* stop caching firmware once syscore_suspend is reached */
1667static int fw_suspend(void)
1668{
1669	fw_cache.state = FW_LOADER_NO_CACHE;
1670	return 0;
1671}
1672
1673static struct syscore_ops fw_syscore_ops = {
1674	.suspend = fw_suspend,
1675};
1676#else
1677static int fw_cache_piggyback_on_request(const char *name)
1678{
1679	return 0;
1680}
1681#endif
1682
1683static void __init fw_cache_init(void)
1684{
1685	spin_lock_init(&fw_cache.lock);
1686	INIT_LIST_HEAD(&fw_cache.head);
1687	fw_cache.state = FW_LOADER_NO_CACHE;
1688
1689#ifdef CONFIG_PM_SLEEP
1690	spin_lock_init(&fw_cache.name_lock);
1691	INIT_LIST_HEAD(&fw_cache.fw_names);
1692
1693	INIT_DELAYED_WORK(&fw_cache.work,
1694			  device_uncache_fw_images_work);
1695
1696	fw_cache.pm_notify.notifier_call = fw_pm_notify;
1697	register_pm_notifier(&fw_cache.pm_notify);
1698
1699	register_syscore_ops(&fw_syscore_ops);
1700#endif
1701}
1702
1703static int __init firmware_class_init(void)
1704{
1705	fw_cache_init();
1706#ifdef CONFIG_FW_LOADER_USER_HELPER
1707	register_reboot_notifier(&fw_shutdown_nb);
1708	return class_register(&firmware_class);
1709#else
1710	return 0;
1711#endif
1712}
1713
1714static void __exit firmware_class_exit(void)
1715{
1716#ifdef CONFIG_PM_SLEEP
1717	unregister_syscore_ops(&fw_syscore_ops);
1718	unregister_pm_notifier(&fw_cache.pm_notify);
1719#endif
1720#ifdef CONFIG_FW_LOADER_USER_HELPER
1721	unregister_reboot_notifier(&fw_shutdown_nb);
1722	class_unregister(&firmware_class);
1723#endif
1724}
1725
1726fs_initcall(firmware_class_init);
1727module_exit(firmware_class_exit);
1728